Add a choose-client command and extend choose-{session,window} to accept a
template. After a choice is made, %% (or %1) in the template is replaced by the
name of the session, window or client suitable for -t and the result executed
as a command. So, for example, "choose-window "killw -t '%%'"" will kill the
selected window.
The defaults if no template is given are (as now) select-window for
choose-window, switch-client for choose-session, and detach-client for
choose-client (now bound to D).
Tiago Cunha